If I were you I'd start by looking through the official demos to get a sense of what the frameworks do. Use the Products menu on this page and follow it through to the relevant demos. Having a good knowledge of the demos is important, you'll waste a lot of time trying to reinvent the wheel if you don't know what already exists. There's no need to study the code at this stage, just play with the demos themselves.

After that try the documentation. There's a link top-right of this page. There are a number of guides and videos available in the documentation that can give you a taste of the frameworks.